Field
Embodiments of the disclosure generally relate to a method and apparatus for encapsulating an organic light emitting diode (OLED).
Description of the Related Art
An OLED is used in the manufacture of television screens, computer monitors, mobile phones, other hand-held devices, etc. for displaying information. OLED displays have gained significant interest recently in display applications due to their faster response time, larger viewing angles, higher contrast, lighter weight, low power and amenability to flexible substrates such as compared to liquid crystal displays (LCD).
OLED structures may have a limited lifetime, characterized by a decrease in electroluminescence efficiency and an increase in drive voltage. A main reason for the degradation of OLED structures is the formation of non-emissive dark spots due to moisture or oxygen ingress. For this reason, OLED structures are typically encapsulated by a buffer layer sandwiched between barrier layers. The buffer layer is utilized to fill any voids or defects in the first barrier layer such that the second barrier layer has a substantially uniform surface for deposition. However, some of the materials utilized to form the buffer layer undesirably generate bubbles at the interface where the barrier layer is in contact with the second barrier layer. Bubbles formed at the interface may adversely be detriment to the film stack adhesion, thus eventfully leading to poor device performance and device failure.
Therefore, an improved method and apparatus for encapsulating an OLED structure is needed.